Fat Dogs, Skinny Cats

Is your dog lethargic and overweight? Does your cat eat everything in sight but still lose weight? They both may suffer from disease of the thyroid gland. Located in the neck, the thyroid gland controls the body’s metabolism.

Dogs often suffer from hypothyroidism, a lack of thyroid hormone production, leading to a slowing of their metabolism. Cats often suffer from hyperthyroidism, an excessive production of thyroid hormone, leading to a speeding up of their metabolism. Hypothyroid dogs usually act lethargic, gain weight, have dry, thin hair coats, may shed excessively and often don’t like the cold weather. Although any dog may suffer from this illness, certain breeds—such as Labrador Retrievers, Doberman Pinschers, and Rottweilers—are more likely to be affected. Hypothyroidism can be diagnosed through a thorough physical examination and blood tests. Special thyroid hormone testing may also be necessary. In many cases, a firm diagnosis is difficult, and your veterinarian may suggest trying testing or trying medication to see if it helps.

Hypothyroidism is treatable but not curable. If diagnosed with the condition, dogs are given oral thyroid hormone replacement medication, usually for life. Most dogs will need to have their thyroid hormone levels checked a few times each year. The good news is that most problems improve with treatment, and many dogs lead normal, healthy lives.

Cats usually have the opposite thyroid problem from their canine friends. Their thyroid gland may develop a benign tumor that produces too much thyroid hormone. This speeds up their metabolism, leading to excessive appetite, with symptoms of weight loss, increased thirst and urination, vomiting and/or diarrhea, and a poor hair coat. Usually, only geriatric cats, those more than eight years old, are affected. Diagnosis is made through physical examination and often a single set of blood tests to check overall body health and a thyroid hormone called T4. Unfortunately, hyperthyroidism can affect many of the cat’s vital organs, including the heart and liver, and may cause significant high blood pressure.

The good news for hyperthyroid cats is that many of them can be cured. A single injection of radioactive iodine, given at a special veterinary facility licensed to handle radiation, is safe and may often be all that is required. Other treatment options include surgery to remove the affected thyroid gland (which often leads to a permanent cure) and oral medications that stop the production of excessive thyroid hormone. The disadvantage of the medications is that while they control the disease, they don’t cure it. These medications must be given for the life of the cat and may have serious side effects. The best treatment plan should be discussed with your veterinarian.

So, if Bowser suddenly acts lethargic and is gaining weight, or Kitty is always eating but losing weight, schedule an examination with your veterinarian to determine whether they are suffering from disease of their thyroid gland.